Flexible coupling



@at 137.1931. c. o. THOMAS FLEXIBLE COUPLING Filed June l1,l 1927 5 Shf-aebs-Sl'xeetl l .WN w VHWHMHM .www

. .1 Nm l mm a .m www @um /fve/z/ar 6'. 7770/7755 Nm A@ Oct. 13, 1931. C, o, THOMAS FLEXIBLE coUPLING Filed June 1l, 1927 3 Sheets-Sheet 2 Oct. 13, 1931. c. o. THOMAS 1,827,176

FLEXIBLE COUPLING Filed June l1, 1927 3 Sheets-Sheet 3 om Q QQ n m @w UW /AAS m i Km RN VWK/V f.

Patented Oct. 13, 1931 ienne y onoii, oiinninvii THOMAS, or MONTREAL, QUEBEC, CANADA FLEXiBLE CQUPLING Application filed 'June' 11,r`

This invention relates to improvements in Couplings 'designed for the connection of shafts' inend to end relation oi'jof gears, pulleys and thelike to shafts, and serviceable `5 also as a universal'joint. y v

ri'lie primary object of the invention is to provide a' flexible coupling, whichv will yield to a limited extent to ove-rloads yimposed upon itan d which will also be ienible to the extent of accommoi'iatingitself to slight misalignment of two shafts. j

A further object is to vprovide a flexible coupling so constructed that the load is distributed uniformly around the circumference oi. the coupling. p i j f A still further object isfto providea rvcouplin o' which may be easily and inexpensivelyV C manufactured." f Y j j Y Various other objects and the advantages of the invention will'be ascertained fromv the following description. ,i

The coupling comprises essentially a p air lof complementary members with mating grooves' th in and a series of 'normally iiurved springs seated in the grooves of the members and Viorming driving Connections vbetween them,- saidsprings' tendingto be ilexed with straightening eiitect upon occurrence ofoverlo-ad conditions inthe coupling. The springsV are each disposed on .onek side ol its longitudinal axis in a groove of one member and ou the other side of its longitudinal anis in the corresponding groove of' the other member. y

In the accompanyingdrawings which illustrate various embodiments of the invent-ion but to which embodiments and the details tliereoiE the invention is not confined l is an end `elevation of thek coupling *J partly broken away to Show theinterior con-v struction and Apartly in section onlthe line 1 1 `of Figure 2.

withr parts c in section on kthe line 2-2y of Figure l. -v Y Fig. 3 is a perspective view ofone form of connecting member. i l v Fig. l is a horizontal development of acnc i cumterential sectionm'gat azone indicated by .ment of the members in case of trillingy mis- 1927. serial No'. 198,172.

' the line. el-fl of Figure 2, and shows connecting springs vin their normal condition. 5 is avview similar to Figure showing the form of the springs under yoverlouil conditions. j l Y Fig. Gis a fragmentary sectional view illustratinga modified form of groove.

Figui? is a hali' central-longitudinal section 'of a coupling designed to have additional resiliency or to Serve as a universal joint.

i Fig-8 is ahalf central longitudinalsection illustrating the couplingkas used to connect a gear, pulley or the like to a shaft. y Fig. y9 is a view similar to Figure2 'illustrating another `adaptation of the deviceto givev added resiliency and to'serve. as anniversal joint,V 1 f Figs. kl0 and l1 are plan views of alternative forms of spring'comiecting members.

Figfl2'is a sectionalview similar to Fig- 70 ureV 5, illustratingy zii-further modiii'edfform of groove.. Y f i l ReferringL more particularly to thel draws ings, 2l and 22 designatethe, male and female members respectively ol a coupling. The male member 21 comprises a hub 23 having` a flange 24 otany suitable diameter formed on its circumferential-surface with .a pluralyity of grooves 25 preferably arranged in yparallelism with theiaXis of the huband preferably formed with straight parallel side walls. The .female member comprisesa hub ,26 having a'flaiige27ol' a diameter suitably' greaterv than the flange of the male member. The iiange `27 has connected thereto a sleeve 28 which, in assembled position of the coupling members, encircles the flange of the maleineniber and is provid-ed with a series of internal grooves 29 'corresponding to, the grooves of the male member, that is to say, of the same number, spacing, shape and relation to the coupling axis. lreferably, a clearance f u 1. 30 exists betw'eenthe sleeve 28 and they liange Fig. 2 isa side elevation of the coupling` 24., so as tovpermit of a slight relative-move.-

. 95 alignment ofthe .shafts 'to which they are connected. l Anend ring 3l is providedon theV `female member and is offsuch Vdimensions as to project radially yinward vfrom the bore of `,thesleeve 28fo`r at least such distance. as'will je cover the ends of the grooves of the mile member. rlfhe sleeve 23 and ringl 3l rigidly connected to the female nier-aber flair; 27 by any suitable means, most conveniently a single set of bolts 32 passing through all three members. lt Will, however, be under Stood that the ring may be independently connected to the sleeve and the sleeve to th flange. Preferably, the internal diameter o the rin@ is an easy slip fit on the end th hub, as indicated by the broken lines in Fig ure 2, lso that vvhen the ring` is disconnecte' from the female member it may be readil moved over the end of the male member liu to give access to the ends of the grooves 25 and 29. The male member hub should be circumferentially channelled as at 33, so that the ring will not bear upon the hub in the case of slight misalignments.

rlhe adjacent faces of the flange 27 and ring` 31 are provided with an annular groove 3d, the grooves of the tivo members being preferably of exactly the same inside and outside diameters. These grooves are provided to receive and hold the ends of the spring inembers which connect the male and female members of the coupling'. lt will be noted that, since the ring 3l is attached to the flange 27, the spring connecting members are carried entirely by the female member of the coupling, but it Will be understood that this is merely a matter of the convenient mechanical arrangement illustrated and that, if desired, the arrangement may be otherwise, even to elimination of the grooves.

Each of the spring connectors, designated as a Whole by the numeral 35, is preferably a full ellipticall springl and may take a variety of forms of Which three are shown in Figures 3, l() and ll. ln each form, the connector comprises a pair of bent leaves 3G formed of preferably flat spring n aterial and arranged with their concave sides facing. rlhe tivo Figure 3, or may be connected as shown in Figures l0 and ll, bv

rivets 37 or other suitable me case of the separate or disconnected leaves, the two leaves of each connector are held in proper operative relation by their asseunbly in the coupling/1` and function exactly if fixed together afterthe manner of Figures 10 and ll. ln the form of connector shown in Figure 3, each of the leaves 36 has one end a tail 33 projecting from the convoi; side of the leaf. The tails 33 curved 'dgeivise as best shown in Figure 3, the radius of curvature conforming to the radius of the grooves 3a in the coupling for which the connectors are adapted. rihe free end of each tail is chamfered, asshown at 39, on what may be termed the inner surface. rlfhe connector leaves of thefform shown in lFigure 3 a l, preferably all alike throughout the coup that when assembled in pairs to produce the elliptical spring connectors, the tails 38 project from one side of the members at one end and from the opposite side at the opposite end. rlhe tails lit snugly in the `grooves 3l and are of such length that, when the connectors are positioned in the sleeve grooves 29, the tails malte contact at their ends with the tailless ends of the leaves of adjoining connectors, as will be clearly from Figures l, l and 5. S aring members of the form shown in Figure l() comprise leaves of the same body formation as in Figure 3, but with shorter tails 38"L arranged both at one end of each connector and arranged for end abutting relation with one another, when assembled in the coupling. The tails 33"L Will naturally have the same edgevvise curvature as the tails 33, so as to accommodate themselves to the annular grooves 34k and, because of the provision of the tails both at one end of each connector, the leaves of these connectors are right hand and left hand. The form of connector shown in Figure ll is Without any tails and may be used in couplings either with or Without annular grooves 31 The connectors are so disposed that each leaf is located on one side of its longitudinal axis in a groove 25 and on the other side of its longitudinal anis in the correspendingl groove 29, the connectors iitting snugly their medial points between the side Walls of the grooves so that, in the event of resistance to movement of the driven meinb of the coupling the connectors will tend to be fla-tte"V ed from the form shown in Figure l to that shown in Figure 5, thus permitting` slight relative angular movement ot 'the coupling member. l

lli'lien the clearance 30 prov" led between the concer 'ric groeved s Y"faces of the coupF r lib-eis, as si'ioivu in Figo. l and there is an upse. ,ng 'tendency or i ndency to rotation al-"out their longitudinal axes eX- erted in the connectors, as 'llust 'ated in Figure G. lf the Walls of the grooves are parallel, 'his tendency causes the load to be concc' t' fred at tlee edges of the grooves with "Vole eilects, among iviiich is in ency to c action of the edges of the @f course the upsetting` or rotating in tbe connectors is resisted by enffae A ont oi. the tails in the `grooves 34.- but, because of vthe resiliency of the connectors, ^l V 'l action in the eon re a possible twist tu leaves which would permit undesiressure at the edges IOOYQG. TO Y i -d to further develop iliency ot the connectors by utilizing ne grooves may be slightly flared from bottom-to top, :is shown to an exaggerated degrooves permits of a slight twisting action being exerted upon the connectors in the op- ,A concentration of r avoid damage to the OVGS il heir resistance to twisting, the side Walls of l in Figure 6. rlhis formation of the ccnnectorsatwise against those walls of the i grooves which are receiving or transmitting force. f Y

A coupling of the simple type shown in Figures i andv 2 has, vas alreadystated, the clearances 30 'and33, which permit the male and female members to adjust themselves vto slight misalignments ofthe shafts to which they are connected, but it is not intention that a coupling of this type should operate under conditions of misalignment such as would ordinarily indicate the use ,of a universal joint. `Wlien these conditions vare lencountered, a double coupling of the type shown in Figure 7 should be employed. ln the double type of coupling, twovexactly similar `male member hubs 2?L are used and may have the flanges thereofr spherically curved from centhe axes of the hubs, as shown at 40. The female member encircles both of Athe male members and bears upon the sphericalf ly curvedk flanges 40, as clearly shown. The female membernia-y be composed of a pair of sleeve members 28'L11 connected to an intermediate ring member 41, or may be otherwise formed as desired. Vlhen a rimT member 4l used, it is preferably diametrically split'to .icllitate the mountingand dismounting of the coupling.' ln the construction illustrated, the intermediate member or its; equivj alent is provided on opposite surfaces with the grooves 34 corresponding to those provided onlthe end rings 31.

Vihen circumstances aermit two sim le Y couplings of the type shown in Figure 2'may be connected to ydrivingand driven shafts and in turnconnected by anintermediate Lshaft 42, as shown in Figure 9. In such an anplication of the coupling, the flanges of the nale members Ymay be 'spherically formed as describedA in connection with Figure 7, and will bear in the `female rmembers.; The re-` mote ends vof the twomale member hubs may be spherically curved from the same centres as their flanges, as shown at 43, and a bear'.- ing ring 44 may be provided in eachfemale member. Pins 45 bedded in the rings and in the female members may be used to hold the rings against rotation independently of the female members. This arrangement is of service when an. end thrust'is'to be transmittedthrough the couplingfor example, in the case of the propeller shaft of a moton .boat orthe like.l `Figure 9 also illustrates the inward projection` of the end rings 3l'L1 past the male member hubs and substantially into contact with the intermediate shaft 42, so as to provide increased accommodation for oil to lubricate the surfaces 40 and 4 8.

, When vanyV considerable amount of mis alignment is providedrfor, rit vis'vdesirable to flare the grooves of the male and female members at their ends, as shown/to an exaggerated extentin Figure l2.' lf this flaringy isj'not two members.

provided, ythe relative movement of the .male and female member grooves at the ends of the axis of oscillation may cause the bearing between the groove walls and connectors to shift from the middle of the groove where the maximum flexibility of the connectors is env` countered to the ends of the grooves, where there is substantially nol-lexibility in the connectors. When thegrooves are longitudinally curved, as shown in Figure l2, to a proper degree, the action is a rolling yone and the bearing points of the connectors and groove walls move only veryv slightly from their. no1'- mal medialposition.' The results of groove curvature are ofk greatest advantagelunder overload conditions such that the connectors are flattened'as in Figure 5.l

lWVhile the invention has heretofore been described only in its application tothe conpreferablykto'the female member and may be provided with annular grooves 52 in which tneends of connectors 35 areseated, the con- Vnectors occupying-the grooves'of the'male and femaley members as already described.

The end rings are attached to` onek ofthe membersan'd are asmoothrunning fit on the other member, so as to maintain the two mem` bersin proper concentric relation. The male member 47 isofcourse connected to a shaft in any usual orsuitableiway.

rl`he operation of the coupling is as follows The male and shown in Figures 2 and 9 or the two male members in the form shown in Figure 7 are rigidly connected to two aligned or apm'oXimately aligned shafts, one of which is the driving shaft and the other the driven shaft. In the absence of the connectors 35, the two coupling members would be independently rotatable but, because of engagement of the connectors each in a groove of the vmale mem, ber and a groove of the female member, a drivingconnection is established between the e 'The number vand strength (resistancekto flexion) oftheconnectors is calculated according to the load to be transmitted through 'the coupling :and Vis preferfemale'members of the form las ablyy such that under normal load and slightly over-load conditions the 'springcony nectors are not iiexed but retain elliptical form. lf the over-load, i. e., re-

sistance to. rotation of .thedriven shaft, isy

their .normal sufficient, the elliptical spring connectors are practically flattened or wholly flattened, as shown in Figure 5. lWhen such flattening occurs, the power transmitting capacity of the connectors is obviously equal to the shearing resistance of the connectors or the strength of metal between the grooves of the male and femaler members. rlfhe yield of the connectors has a cushioning" effect which is obviously very beneficial in absorbing sudden shocks both in a machine driven through the coupling` and in a prime mover supplying power through the coupling. The effect of the spring connectors is therefore to cause a gradual application of both power and load above a certain amount which is the force necessary to initiate flexion of the connectors. Yielding of the connectors either by flattening or by twisting is accompanied by slight relative rotation of the coupling parts, as shown by comparison of Figures L and 5, and also by Figure 6. llfhe the overload on the flattened or twisted connectors falls below their reactive effort, they tend to return the coupling members to 'their or inal relation. `When a great amount of cushioning effect is desired, a. plurality of sets of connectors may be coupled in series, for example, as shown in Figure T, which illustrates a simple arrangement of this charactr. A still greater amount of flexibility may be obtained by using two or more couplings of the type shown in Figure 7 in the manner shown in Figure 9. Nhile the two series of connectors are arranged end to end, it will be understood `that this; is not essential and that some other relation of the series may be established. lt will be obvious that with a constant amount of possible in the connectors the `:esulting` relative angular noi-'emci'it of the couplingparts is greater with the connectors arranged on small pitch circles than on large, and it is also evident that for the same number of connectors of the same resistance to flexion the angular flexibility of the coupling is greater when the connectors are arranged on small pitch circles than on large. Thus, the load transmitting capacity of a coupling before flexion of the connectors occurs may be increased by increasing the pitch circle on which the couplers are arranged or by incr-iasing the number of couplers on a given pitch circle. ln the former case, the possible relative angular moveniient of the parts is decreased, while in the latter Case it is not. Obviously. variations in the transmission capacity of the coupling may be effected by using connectors more or less flexible. ln'- creasing the size of the pitch circle on which the connectors are arranged enables the use of more connectors of given size without reducing the amount of metal between the grooves of the members or, on the other hand, enables the use of more greatly arched connectors. vlt is possible without unreasonably increasing the pitch circle diameter with relation to the shafts to employ enoughr connectors so that the total force transmitting capacity will be greater than the strength of the shafts.

lf the two shafts are very slightly out of alignment, the clearances between the male and female members enable the coupling to adjust itself to the misalignment without imposing any additional load on the connectors unless over-load is encountered sufficient to completely fiat-ten the connectors. To meet such a. condition, especially if the misalignment is considerable, the side walls of the grooves may be longitudinally curved, as shown in Figure l2. ln any case, only those connectors at or close to the ends of the axis of oscillation will be affected. With clearances between the grooved surfaces of the members, shown in Figures l and 2, the transmission of force through the coupling produces an upsetting tendency in the con nectors, as shown in Figure 6. When con nectors with tails are used, this upsetting is resisted by engagement of the tails in the grooves Se, with the result that the connectors are subjected to a twisting action in addition to the flattening action. lVith parv allel walled grooves, the contact between the grooves and connectors may therefore be r garded as being at the edges of the grooves. lWhen the groove walls are very slightly flared from bottom to top, the normal contact of the groove walls and connectors is close to the bottoms of the grooves, so that a maximum twisting effort is exerted upon the connectors. As the connectors yield, the relation shown in Figure 6' is approached or attained, and the effect is to shift the loading points on the connectors from the bottoms of the grooves toward the clearance, thus decreasing the effectiveness of the twisting effort. This formation therefore has the effect of relieving the eXtreme edges of the grooves of much load, especially under overload conditions and, therefore, of prolonging the life thereof. Further, it enables the twisting resistance of the connectors to be utilized as well as their resistance to flattening. V17 hen the grooved surfaces of the male and female members are actually in Contact, as shown in Figures 7, 8 and 9, the same advantages are realized by the flaring groove formation of Figure 6, though to a lesser extent, especially under over-load conditions which result in flattening of the connectors. 1 Y

lf a connector leaf should break, it may be very easily replaced by removing the bolts 32 and sliding the ring 3l and sleeve 28 in the axial direction of the coupling. Owing to the expansive action of the connectors which will hold them in the grooves of the male member, the sleeve may be removed without displacing the connectors from the male member, so that the connectors may be inspected and. any damaged onesV yrenewed and the sleeve then returned to position. If

the broken connector has its tail bedded in the ring 3l, the broken leaf may be renewed and a fresh leaf inserted without displacing the sleeve 28 or, in the case of connectors shown Lin Figures l and ll, the entire connectorimay be removed and replacedupon removal of the ring 3l only. A further advantage of the ltype of connector shown in lFigures IO and 11 isthat, if desired, they may be withdrawn without any precautions for retention of the connectors.

The connectors, as shown in either Figures 3 or 10, are designed to malte contact with one another inthe grooves 34, so that if, by

any chance, a groove should be mal-formed.

or wear faster than adjoining grooves, load will be transmitted from one connector-to the next through the tails thereof to effect load distribution and avoid over-loading or under-loading in one connector. Because of this contact between the connectors, the ends of their tails are chamfered, as at 39, to facilitate insertion as will be readily understood.

ror the Ynumber of connectors.

" The action of the connectors in applications of the invention, such as shown in Figure 8, is exactly the same as already described.

From the foregoing description and the drawings, it will be readily seen that (disregarding the connectors) the coupling consists of only a' few partswhich may be readily produced at low cost. The connectors themselves are simpley and may be very easily and cheaply manufactured, The breaking of one or even of several connector leaves ina coupling will not materially reduce the capacity of the coupling and will not render it inoperative. Couplings may be readily designed to have any desired capacityand flexibility by suitably varying the diameter of the pitch circle on which the connectors are arranged Obviously, the load and cushioning capacities of any given coupling may be varied by substituting connectors of greater orfless flexibility and the great advantages of this last capability will be obvious. l

Vhile'certain embodiments of the invention and certain details thereof have been illustrated, it will be understood that the invention is not confined to these'embodiments or details, as other embodiments may be made as well as alterations of details and combinations of details. y y Having thus described I claim is p l. In a coupling, outer and inner members my invention, what having concentrically related surfaces pro-V vided with mating grooves disposedparallel with the axis of the members and a series vof springs carried by the outer member and engaged only at their central parts inthe grooves of both members and forming flexible driving connections between'tliemembers. Y' f f 2. In a coupling, outer and inner members having concentrically related surfaces provided with mating grooves disposedparallel with the axis of" the members and a series springs engaged intermediate Ytheir ends in `the grooves of both members and held at their ends by the outer member only, said springs forming flexible driving connections between the members. j

3. In a coupling, male and `female members having concentrically related surfaces provided with mating grooves parallel with the axis of the members, said female member including two annularly grooved portions and a series of spring connectors mounted at their ends in the annular grooves of the female member and disposed intermediate.

their ends in the grooves of the male and female members.

41. In a coupling, a male member including a flange having the edge thereof provided with a series of grooves parallel with vthe member axis, a `female member encircling and shrouding the grooved portion of the male memberflange, said female member presenting an internally grooved surface, the grooves.

of whichmate with the grooves of tliemale member, saidfemale member being further provided with a pair of annular grooves disposed one on either side of the male member flange, and aseries kof spring connectors located at their ends in said annular grooves nd located at their intermediate portions in the mating grooves of the male and female members.

5. In a coupling, a male member including a flange formed in its edge with a series .of grooves disposed parallelfwith the member axis, a female member including a flange of greater` diameter thanthe male member flange a sleeve carried by said female member flange encircling the male member flange and provided internally with grooves mating with the male member grooves, and an end ring carried byv said sleeve shrouding the ends of the sleeve grooves and male member grooves, and springconnectors carried bythe female member disposedin the groovesA of the'male and female members and held at their endslindependently of said grooves by the. female member llange and theendring.

6. In a coupling', a male member including a flange formed in its edge with a series of grooves disposed parallel with the member axis, a female member including a flange of greaterdiameterthan the maleinember'flange, a sleeve carriedby saidfemale member flange encirclino` the male member flange and provided internally .vith grooves mating` with the male member grooves, an end ring carried by said sleeve shrouding the ends of the sleeve grooves and male member grooves, saidL female member flange and said end ring bcing formed on their'adjacent surfaces With annular grooves opposite the ends of the mating grooves, and spring connectors located at their ends in said annular grooves and located their intermediate portions in the mating grooves thereby to connect the male and fe male members.

7. ln a coupling, a male member including a flange formed in its edge with a series of grooves disposed parallel with the member anis, a female member including a Hang-e of greater diameter than the male member flange, a sleeve carried by said female member flange encircling the male member flange and provided internally With grooves mating With the male member grooves, an end ring carried by said sleeve shrouding the ends of the sleeve grooves and male member grooves, said female member flange and said end ring being formed on their adjacent surfaces with annular grooves opposite the ends of thev mating grooves, and elliptical spring connectors located at their ends in said annular grooves and at their intermediate po-rtions in the mating grooves in p-osition to be flexed With flattening tendency upon relative angular movement of the male and female members.

8. ln a coupling, a male member including a flange formed in its edge with. a series of grooves disposed parallel with the member axis, a female member including a flange of greater diameter than the male member flange, a sleeve carried by said female member flange encircling the male member vflange and provided internally with grooves mating With the male member grooves, an end ring carried by said sleeve shrouding the ends of the sleeve grooves and male member grooves, said female member flange and said end ring boing formed on their adjacent surfaces with annular grooves opposite the ends of the mating grooves, and spring connectors located at th intermediate portions in the mating grooves and including tail portions located in said annular grooves.

9. In a coupling, a pair of concentrically arranged members provided With mating grooves disposed parallel with the axis of the members, and a series of leaf springs normally curved from end to end and in the axial direction of the members each located partly in a groove of one member and partly in the mating groove of the other member and adapted to be iieXed With flattenin` tendency upon relative angular movement of the members.

l0. In a coupling, a pair of concentrically arranged members provided with mating grooves disposed parallel. with the axis of the in a groove of one member and the other ap- 'proximately longitudinal half located in the mating groove of the other member and adapted to be flexed with flattening tendency upon relative angular movement of the members.

ll. ln a coupling, a pair of concentrically arranged members provided With mating grooves disposed parallel with the axis of the members, and a series of elliptical springs arranged parallel with the members in the grooves thereof and each normally contacting only at its central portion with the sides of the grooves.

l2. ln a coupling, a pair of concentrically arranged relatively oscillatable members formed with mating grooves substantially parallel with the member axes, and a series of elliptical sprii located in the member grooves substantially axially parallel with the members and adapted to be compressed upon relative rotation of the members.

i3. ln a coupling, a pair of concentrically arranged relatively oscillatable members formed with mating grooves substantially parallel With the member axes and a series of leaf springs normally curved in their longitudinal directions and located lengtl Wise in the member grooves in position to be flexed with flattening tendency upon relative rotation of the members.

le. ln a coupling, a pair of concentrically arranged relatively oscillatable members formed with mating grooves substantiall f parallel with the member axes and a series of leaf springs normally curved in their longitudinal directions and arranged each with approximately one longitudinal half 1n a groove of one member and approximately the other longitudinal half in the mating groove of the other member whereby all said springs Will be flexed With flattening tendency upon relative rotation of the members.

l5. In a coupling, a pair of members presenting substantially concentric adjacent surfaces formed with a plurality of mating grooves, and a series of spring members located in the mating grooves in position to be partially rotated about their longitudinal axes upon relative angular movement of the coupling members, and means holding said spring members at their ends against rotation, whereby upon tendency to relative angular movement of the coupling members the spring members are subjected to torsional stress.

16. ln a coupling, a pair of members presenting substantially concentric adjacent surfaces formed with mating grooves therein, a series of spring members located in the mating `grooves in position4 to be partially rotated about their longitudinal axesupon relative angular movement .of the coupling members, said spring members including tails seated ina recess formed therefor in one of the coupling members to hold the spring members rotation at their ends, whereby upon relative angular movement of the coupling members the spring'members are subjected/to torsional stress. i .17. ln a coupling, a pair ofmembers presenting concentric adjacent surfaces formed with mating grooves, one of said members being additionally provided opposite the ends of said mating grooves with an annular `groove, a series of spring members of strip form located in the mating grooves and tending to be rotated aboutl their longitudinal axes upon relative angular movement of the coupling members, and tails projecting laterally from said spring members and seated in said annular groove to resist rotation of the spring members, whereby upon relative angular movement of the coupling members, the spring members are subjected to torsional stress.

i8. ln a coupling, a pair of members presenting substantially concentric surfaces formed with mating grooves, `one of said members being formed adjacent the ends of the mating grooves with an annulaigroove, a series of normally curved spring members located in the mating grooves in position to be flexed with straightening effect upon relative angular movement of the members and to simultaneously have imparted thereto a tendency to rotation about their longitudinal axes, and tails on said spring members seated in the annular groove and resisting the tendencyl to rotation,I whereby the'spring members are also subjected to torsional stress.

19. In a coupling, a pair of members presenting concentric surfaces formed with mating grooves, the side Walls of said grooves diverging slightly from thebottoms to the tops of the grooves, and spring members of strip form located in said grooves and normally bearing against the side Walls of the grooves adjacent the bottoms thereof, said spring members operating to resist relative angular movement of the coupling members and tending to be rotated about their longitudinal axes bv tendency to relative angular movement of the coupling members, thereby to shift the points of enga-gement of the spring members and groove Walls town rd the tops of the grooves. Y ,Y c

20. ln a coupling, a pairof members presenting con centric surfaces formed With mating grooves, the side Walls of said grooves diveroing slightly from the bottoms to the tops of the grooves, spring members of strip f form located in said grooves and normally bearing against the side Walls of the grooves adjacent the lbottoms thereof, said spring membersoperating to resist relative angular movement of the coupling members and tendment of the .coupling members thereby to shift the points vof engagement of the spring members and groove walls toward the tops ofthe grooves, and tails on said members bedded in an annular groove provided. there-k for in one of the members and operating to resist rotation of the spring members Whereby the same are subjected to torsional stress.

2l. A. device according` to claim 8 infivhich the tails of the spring connectors are curved edgfjevvise in conformity With curvature of ythe annular grooves into Which they fit.

22. A device according to claim 8, in which the spring connectors each comprise a pair of oppositely curved vleaves and in which the tails project at opposite sides of the connectors.` l 19.3. A coupling comprising a pair of members having mating grooves therein and a series of separate springs located in the grooves and forming driving connection betui-ten the members, each of said springs being in contact With the adjacent springs for equalization of load entirely around the coupling.

-el. A coupling comprising apair of members having normally' concentric surfaces formed with mating grooves and a series of separate springs extending substantially parallel with the coupling axis located in the grooves and forming driving connection bev tween the members,each of said springs beingin contact with the adjacent springs for equalization of load entirely around the coupling. 1

25. A coupling comprising a pair of members having normally concentric surfaces formed with mating grooves and a series ofA separate springs extending substantially parallel with the coupling aXis located in the grooves and forming driving connection between the members, each of said springs comprising a pair of leaves normally curved from end to end and a pair of laterally and oppo- Ysitely extending tail portions engaging adjacent springs for equalization of load.

26. A coupling comprising a pair of members having normally concentric surfaces formed with mating grooves having the side Walls thereof slightly iiared from bottom to top, andsprings normally curved from end to end located lengthwise in the grooves and forming yielding driving. connection between the members, said springs normally engaging the groove Walls only near the groove bottoms and being'normally spaced from the groove `walls at the tops whereby relative rotation. of the members Vtends to cause each spring to rotate about its 'own axis. i

27. A coupling comprising a pair of members having normally concentric surfaces formed With mating grooves, and springs nor- ,i an

mally curved from end to end located lengthvcise in the grooves and forming yielding dri\ ing connection between the members, the grooved surfaces ofthe members being spaced to induce rotation of the springs about aires parallel with the coupling ams and the walls of the grooves being flared from bottom to top to aiford surface engagement for the springs upon rotation thereof and to reduce the ro tating force applied to the springs.

28. A coupling comprising a pair of members having normally concentric surfaces formed with mating grooves, and springs normally curved from end to end located lengthwise in the grooves and ing yielding driving connection b 'L veen the n embers, tie grooved surfaces the members being spaced to induce rotation of the springs about axes parallel will the coupling axis and thc Valls of the grooves being flared from bottom to top to aiford surface engagement for the springs upon rotation thereof and to reduce the rotating force applied to the springs, and means holding the springs at their ends against rotation whereby the springs are subjected to tos-sional stress.

29. A coupling comprising a pair of men bers having normally concentric surfaces formed With mating grooves disposed substantially parallel with the coupling axis, and a series of leaf springs engaged at their' entral portions in the grooves of said members and forming driving connection between the members, said springs being Vadapted to be partially rotated about longitudinal axes parallel with the coupling axis, and means holding the springs at their ends against rotation, whereby the springs are subjected to torsional stress res'sting relativeA rotation of the members.

30. A structure according to claim 29, in which the springs are elliptical and by resistance to flattening further resist relative rotation of the members.

3l. il structure according to claim 29, in which one of the members is formed with recesses receiving the ends of the springs to bold them against rotation as aforesaid.

32. In a coupling, concentrically arranged male and female members formed in their adjacent surfaces with mating `grooves disposed parallel \vith the axis of the members and a series of normally curved leaf springs each disposed With substantially one longitudinal half in a groove of the male member and substantially the other longitudinal half in the mating -oroove of the female member, said springs being flexible in the circumferential direction of the coupling with flattening tendency.

ln a coupling, concentrically arranged male and female members formed in their adjacent surfaces With mating grooves disposed parallel with the axis of the members, and a series of normally curved leaf springs each disposed With substantially one longitudinal half in a groove of the male member and substantially the other longitudinal. half in the mating groove of the female member, said springs being flexible in the circumferential direction of the coupling with flattening tendency, and said female member being formed with circular grooves in which the ends of the springs are engaged.

Sel. ln a coupling, concentrically arranged male and female members formed in their adjacent surfaces with mating grooves disposed parallel with the axis of the members, and a series of normally curved leaf springs each disposed with substantially one iongis tudinal half in a groove of the male member and substantially the other longitudinal half in the mating groove of the female member, said springs being arranged in pairs with their concave surfaces facing and their ends in contact forming elliptical structures enthe side Walls of the grooves at their medial points and compressible in the circumferential direction of the coupling.

35. ln a coupling, concentrically arranged male and female members formed in their adjacent surfaces With mating grooves disposed parallel With the axis of the members, said female member being formed with circular grooves facing the ends of the parallel grooves, and a series of normally curved leaf springs -eath disposed with substantially one longitudinal half in a groove of the male member and substantially the other longitudinal half in the mating groove of the female member, said springs being flexible in the circumferential direction of the coupling With flattening tendency, and includ ing laterally directed tails fitting snugly in said circular grooves.

355. l'n a coupling, a pair of members presenting parallel surfaces formed 1with mating grooves, the side `Valls of said grooves being itl-.y convezily curved from end to end, and spring members located in the mating grooves and forming driving connection between the coupling members.

ln a coupling, pair of members presentin parallel surfaces formed with mating grooves, the `side Walls of said grooves being sight-ly convexly curved from end to end, and a series of normally curved spring mombers located in said mating grooves and adapted to be flexed with straightening tendency upon relative angular movement of the coupling members.

38. ln a couplin a pair of members presenting parallel surfaces formed with mating grooves, the side vralls of said grooves being sli glitlv convexly curved from end to end, and a series of elliptical spring members disposer in said mating grooves position to be compressed with straightening effect vupon relative angular movement of the coupling' members.

39. In a coupling,'a pair of members provided with mating grooves disposed parallel be with the axis of the members, the side walls of said grooves being longitudinally convexly my han d. i p CECIL OLDRIEVE THOMAS. `70

centered in the male member aXis and bearing f in the cylindically formed surface of the female member, said members being formed with mating grooves in the cylindrical and spherical surfaces thereof, and a series of spring members located in the mating grooves and forming driving connection be-.

tween the members. y

41. In a coupling, afemale member presenting a cylindrically formed inner surface co-aXial with the member axis, a male memf ber presenting a spherically formed portion centered in the male member axis and bearing in the cylindrically formed surface of the female member, said members being formed with mating grooves' inthe cylindrical and spherical surfaces thereof, and elliptical spring members located in the matingv grooves and forming driving connection between the coupling members.

42. In a. coupling, a female member presenting a cylindically formed inner surface 3o-axial with thevmember axis, a male member presenting a spherically formed portion centered in the male member axis and bearing in the cylindrically formed surface of the female membensaid members being formed with mating grooves in the cylindrical and spherical surfaces thereof, each of said grooves having the side walls thereof convexly curved, and spring members located in the grooves and forming driving connections between the coupling members.

43. In a coupling, members formed with a plurality of series ofv inwardly facing grooves and members formed with a plurality of series of outwardly facing grooves mating with the inwardly facing grooves, and a plurality of series ofelliptical spring members located in said mating grooves in positon to becompressed upon relative angular movement of the members.

44. In a coupling, a pair of female members formed with inwardly facing grooves, a pair of male members formed with outwardly facing grooves mating ywith the grooves of the female membersconnection between the two members of one sort, and

v normally curved spring members disposed in the mating grooves and forming driving connections between the male and female'memrs. In witness whereof, I have hereunto set l 

